Viscosimeter



United States Patent 3,187,563 VISCGSENETER Philip E. Tobias, 1872 Watson Road, Ahington, Pa. Fiied May it), 1962, Sea. No. 193,766

Claims. (ill. 73-56) This invention relates to a viscosimeter, and more specifically relates to a viscosimeter which is automatic in operation.

There are many applications which utilize fluids of various types wherein the viscosity of the fluid should be constantly monitored. Such an application is in the use of fluid inks such .as those employed in Gravure and Plenographic industries wherein a close relationship has been found to exist between the viscosity of the ink used and the resulting printing quality.

The common manner for measuring this viscosity has (been a hand operation which employs a cup having a hole or capillary at the bottom thereof. type are modifications of the so-called Zahn cup wherein the operator fills the 'cup to the tip while holding his finger over the capillary. Thereafter, the capillary is opened and the time required for the. cup to empty is measured. This time will give a direct measurement of the viscosity of the ink whereby the viscosity of the ink can be modified by the addition of solvents or solids, as required.

To maintain the uniform quality of printing, it i-s necessary that this manual operation be continually carried out at frequent intervals so that it is expensive, extremely inconvenient, and is subject to subjective errors of interpretation.

The present invention provides a novel manner wherein such viscosity measurements may be automatically made without the requirement of a human attendant.

More specifically, and in accordance with the invention, a Za-hn cup-"type arrangement having a capillary at the bottom with a spout at an upper end thereof is placed in registry with a source of a fluid sample to be measured which is controlled by a solenoid-operated valve. The capillary is in registry with a first fluidoperated switch, while the spout is in registry with a second fluid-operated switch. A cycle timer is connected to the solenoid-operated valve and controls the flow of ink to the cup. This cycle timer is such that it will permit suflicient flow of ink to completely fill the cup above the spout level, although ink flows from the capillary.

Once the ink is completely filled, a timer mechanism.

connected to the cycle timer so that it may be energized when the cycle timer is de-energized, is then connected Cups of this in series with the switch contacts of the capillary switch and spout switch.

The cycle timer automatically shuts oli the solenoid valve so that the level of ink decreases'to a point at which the spout is above the ink level. So long as ink flows from the spout, the switch contact associated there- 9 with is open so the timer is not energized. y r

So long as ink flows from thecapillary, the switch contact associated therewith is closed. Once the fluid ievel falls below'the spout, the switch contact associated net 31, and is contained within the housing 34a.

to open the solvent or sol-id valve lines to maintain the viscosity of the ink at some predetermined value.

()ncethe cycle timer again operates to refill the cup, it also delivers a signal to the timer to reset the timer back to its zero value so that a new reading can be made.

Accordingly, a primary object of this invention is to provide an automatic viscosimeter.

Another object of this invention is to provide a novel automatic system for continually monitoring the viscosity of the fluid.

A further object of this invention is to provide a novel viscosimeter which does not require the attendance of a human operator and which is free of subjective errors.

These and other objects of the invention will become more apparent from the following description of the drawing which shows a schematic diagram of an automatic viscosimeter constructed in accordance with the invention.

Referring to the drawing, I have illustrated therein a cup 16 which has a capillary tube outlet 11 at the lower end thereof and a spout 12 at the upper end thereof. The cup. is placed in registry with the outlet 13 of a valve 14 having an inlet opening 15 and which is operated by a solenoid contained within solenoid housing portion 16. The fluid entering inlet 15 can, for example, be a sample tapped from the main fluid supply of a process in which the viscosity of the fluid is of great importance as, for example, in the use of fluid ink in various types of printing operations.

The cup is carried between two side walls and 21 of a support chassis which are partially shown in perspective view. Walls 20 and 21 have wire-receiving fittings 22 and 23 respectively which are arranged to carry a taut .wire 24. In a similar manner, lower portions of walls 20 and 21 have identical wire fittings 25 and 26 which carry a taut wire 27. i

A van-e 28 is then carried on taut wire 24- in the manner illustrated so that it is pivotal in a low friction manner on wire 24, although wire 24 normally biases vane 28 to a predetermined angular position. A similar vane 2? is carried on Wire 27 so that it may be rotated with Wire 27 in a relatively low friction manner.

The ends of each of vanes 28 and 29 then carry 'U-shaped' permanent magnets 30 and 31 respectively which are so balanced on vanes 28 and 29 that the complete assembly normally assumes a preferred angular position. I

Permanent magnet 30 is carried adjacent a contact housing 32 which carries therein a fixed contact structure 33 and a relatively movable contact structure 64, wherein the movable contact structure 34 responds to the magnetic field of magnet 30. When the vane 28 is in its.

normally balanced position, the magnetic field of mag net 30 exerts a force upon movable contact structure 34 so as to engage contact structures 33 and '34. p

A similar contact arrangement is placed adjacent mag- The contacts within housing 34a, however, are slightly differently arranged, whereby the stationary contact structure 35 and movable contact structure 36 are disengaged when magnet 31 and vane 29 are in their norm-a1 angular positions. Thus, the contacts ,33: and 34 arenormal-ly open contacts, while contacts 35 and 36 are nor mally closed contacts;

These contacts are then connected in series with one another and. with the energizing mechanism of an electrically operable timer' 4t! and in further series with an input A.-C. line 41. The timer 40 may be of any standard commercially available type which can be automatically electrically reset with the reset connections 42 extending to a cycle timer mechanism 43. mechanism 43 is energized by a line 44 which could be a tap on the line 41, if desired. The output of cycle timer 43 is connected to the solenoid within housing 16 of solenoid valve 14 and is so arranged that it will deliver an output voltage for a predetermined length of time over predetermined intervals. Moreover, so long as cycle timer 43 energizes valve 14, the timer 40 is held inoperative by circuits energized from connections 42.

In accordance with the invention, the cycle timer is arranged to connect the line 44 to solenoid valve 16 for as long a time as is necessary to permit fluid flow from line to cup 10 of sufiicient volume to fill cup in above the level of spout 12, even though there is continuous leakage from capillary 11.

While the cup 10 is being filled, the vane 29 is rotated under the pressure of the flow of fluid from capillary 11. This rotation removes magnet 31 from an operating position with respect to contact 36, whereby contact 36 moves to an engaged position with respect to contact 35. The cup is rapidly filled so that there is eventually an overflow from spout 12. This overflow will rotate Vane 28 so that magnet 3% is removed from its operating position with respect to contact 34, whereby the contact 34 moves to its normally open position.

Once the cycle timer interval ends, the timer mechanism is abled and can begin a timing operation. However, until the fluid in the cup falls to below the level of spout 12, contacts 33 and 34 are open so that the timer circuit is open. Once the level of fluid within cup 10 falls to a level immediately below spout 12, the fluid flow pressure is removed from vane 28. Magnet then returns to its operating position with respect to contact arm 34 whereby contact 33 and 34 are closed to complete the circuit from line 14 to timer '40, and a time measurement is commenced- Once the cup 10 is completely emptied through capillary 1 1, the pressureon vane 29 is removed, whereby magnet 31 is returned to its operating position with respect to contact structure 36 so that contacts 35 and 36 are disengaged to t le-energize timer 40. Thus, the timer 40 has measured the length of time required for the cup 10 to empty from the level of spout 1-2.

This time measurement can be calibrated on timer 40 in terms of viscosity, whereby a direct measurement of viscosity can be easily made. Some predetermined time later, the cycle timer 43 again initiates a new measuring interval, whereby it also delivers a signal over lines 42 to reset timer 4Q.

From the above, it is seen that a simple method of continuously monitoring the viscosity of the ink is provided in accordance with the present invention. This system does away with the need for a human operator continuously making the measurement, and it does away with any subjective errors that the human opertor may introduce into the measurement.

As a further feature of the invention, it is possible to connect the output final reading of timer 40 to; an appropriate servo system which controls the addition of solvents or. solids to the main ink body, whereby the existence of too long a time measurement or tooshort a time measurement initiates a change in the viscosity of the fluid in an appropriate manner.

Inthe foregoing, the fluid-responsive contacts were described as pressure-operateddevices.- It will be apparent that the switches are more generally respond to presence of a flow of fluid.

Moreover, and within the general conceptof the invention, any signaling means could be used to indicate the proper height of fluid within the cup so that the time measurement by the closed contact which responds to fluid flow from the capillary or leakcan commence.

of any type that Although this invention has been described with re-.

spect to its preferred embodiments, it should'be understood that many variations and modifications will now be'obvious to those skilled in the art, and it is preferred,

Cycle timer timer mechanism, an electrically operable valve for said therefore, that the scope of this invention be limited not by the specific disclosure herein but only by the appended claims What is claimed is:

1. A viscosimeter comprising a cup means having a controlled leak at the bottom and a spout at an upper portion thereof, a first and second switching means having first and second contacts respectively, and an electrically operable timer mechanism; said first and second switching means being operable to operate their said contacts between engaged and disengaged positions responsive to the flow of fluid from :said controlled leak and said spout respectively; said first contacts being closed responsive to flow of fluid from said controlled leak; said second contacts being opened responsive to flow of fluid from said spout; a voltage source; said voltage source, said timer mechanism, said first contacts and said second contacts being connected in series.

2. In a viscosimeter; a cup means adapted to contain fluid from a source of fluid and having a controlled leak at the bottom and a spout at an upper portion thereof, a first and second switching means having first and second contacts respectively, and an electrically operable timer mechanism; an electrically operable valve for said source of fluid, and a cycle timerfor opening and closing said valve in a predetermined sequence; said first and second switching means beingoperable to operate their said contacts between engaged and disengaged positions responsive to the flow of fluid from said controlled leak and said spout respectively; said first contacts being closed responsive to flow of fluid from said controlled leak; said second contacts being opened responsive to flow of fluid from said spout; a voltage source; said voltage source, said timer mechanism, said first contacts and said second contacts being connected in series; said cycle timer permitting flow of fluid to said cup for at least as long as required to fill said cup past the level of said spout.

3. In a viscosimeter; a' cup means adapted to contain fluid from a source of fluid and having a controlled leak at the bottom anda spout at an upper portion thereof, a first and second switching means having first and second contacts respectively, and an electrically operable timer mechanism, an electrically operable valve for said source of fluid, and a cycle timer for opening and closing said valve in a predetermined sequence; said first and second switching means being operable to operate their said contacts between engaged and disengaged positions responsive to the flow of fluid from said controlled leak and said spout respectively; said first contacts being closed responsive to flow of fluid from said controlled leak; said sec ond contacts being opened responsive to flow of fluid from said spout; a voltage source; said voltage source, said timer mechanism, said first contacts and said second contacts being connected in series; said cycle timer permitting flow of fluid to said cup for at least as long-as required to fill said cup past the level of said spout; said cycle timer being electrically connected to said electrically energizable timer and rendering said timer inoperative while said valve is held open. i a v A. In a viscosimeter; a cup means adapted to contain fluid'from a source of fluid and having a controlled leak at the bottom and a spout at an upper portion thereof, a first and second switching means having first and second contacts respectively, and an electrically operable source of 'fluid,'and a cycle timer for openin and closing; said valve in a predetermined sequence; said first and second switching means being operable to operate their said contacts between engaged and disengaged positions responsive to the flow of fluid from said controlled leak and said spout respectively; said first contacts being closed responsive to flow of fluid from said controlled leak; said second contacts being openedresponsive to flow of fluid from said spout; a voltage source; said voltage source, said timer mechanism, saidfirst contacts and said second contacts being connected in series; said cycle timer per-.

mitting flow of fluid to said cup for at least as long as required to fill said cup past the level of said spout; said cycle timer being electrically connected to said electrically energizable timer and rendering said timer inoperative while said valve is held open; said cycle timer resetting said timer when said valve is opened.

5. In a viscosimeter; a cup means adapted to contain fluid from a source of fluid and having a controlled leak at the bottom and a spout at an upper portion thereof, a first and second switching means having first and second contacts respectively, and an electrically operable timer mechanism, an electrically operable valve for said source of fluid, and a cycle timer for opening and closing said valve in a predetermined sequence; said first and second switching means being operable to operate their said contacts between engaged and disengaged positions responsive to the flow of fluid from said controlled leak and said spout respectively; said first contacts being closed responsive to flow of fluid from said controlled leak; said second contacts being opened responsive to flow of fluid from said spout; a voltage source; said voltage source, said timer mechanism, said first contacts and said second contacts being connected in series; said cycle timer permitting flow of fluid to said cup for at least as long as required to fill said cup past the level of said spout; said cycle timer being electrically connected to said electrically energizable timer and rendering said timer inoperative while said valve is held open; said cycle timer resetting said timer when said valve is opened; said first and second switching means being responsive to pressure due to flow of fluid from said controlled leak and said spout respectively.

References Cited by the Examiner UNITED STATES PATENTS 2,150,545 3/39 Fairbairn 73-56 2,333,791 11/43 Hutchinson 73-194 3,074,266 1/63 Sadler et a1. 7355 FOREIGN PATENTS 537,548 5/22 France. 649,933 9/28 France.

RICHARD C. QUEISSER, Primary Examiner.

JOSEPH P. STRIZA-K, Examiner. 

1. A VISCOSIMETER COMPRISING A CUP MEANS HAVING A CONTROLLED LEAK AT THE BOTTOM AND A SPOUTH AT AN UPPER PORTION THEREOF, A FIRST AND SECOND SWITCHING MEANS HAVING FIRST AND SECOND CONTACTS RESPECTIVELY, AND AN ELECTRICALLY OPERABLE TIMER MECHANISM; SAID FIRST AND SECOND SWITCHING MEANS BEING OPERABLE TO OPERATE THEIR SAID CONTACTS BETWEEN ENGAGED AND DISENGAGED POSITIONS RESPONSSIVE TO THE FLOW OF FLUID FROM SAID CONTROLLED LEAK AND SAID SPOUT RESPECTIVELY; SAID FIRST CONTACTS BEING CLOSED RESPONSIVE TO FLOW OF FLUID FROM SAID CONTROLLED LEAK; SAID SECOND CONTACTS BEING OPENED RESPONSIVE TO FLOW OF FLUID FROM SAID SPOUT; A VOLTAGE SOURCE; SAID VOLTAGE SOURCE, SAID TIMER MECHANISM, SAID FIRST CONTACTS AND SAID SECOND CONTACTS BEING CONNECTED IN SERIES. 